A Little History of R/C
Radio Control could be summarised by saying that Person A controls Object B via a radio connection. Person A has a transmitting device, and Object B has a receiving device connected to a series of motors called "servo's" that actually do the work.
Wireless telegraphy is not new, Tesla demonstrated its use in 1893, and in 1894 Jagdish Chandra Bose used electromagnetic waves to ignite gun powder and strike a gong in Calcutta in India. In 1896 Tesla transmitted signals for nearly 30 miles distance, and in 1899 Marconi spanned the English Channel with his transmission.
The challenge for all of this though, in respect to modellers, was the size of the gear. It wasn't until prior to the 2nd World War and the invention of vacuum tubes or "valves" that the equipment became small enough to consider controlling full sized aircraft, and this was experimented during WWII by the Germans in their missiles.
Up till his period in our history, model aircraft could be classified either as:
Free Flight - where the aircraft was launched into the air, maybe with an engine, and flew by itself ideally in an orbit around the person on the ground
Control Line - where the powered aircraft is connected to a person by a series of lines attached to a control handle held by the "pilot". The aircraft flies in a circle around the "pilot" and the elevator is controlled by movement of this handle. Less popular these days, you can still buy control line models at hobby stores, and I bought one for my son when he was 11 to let him get familiar with controlling a model.
The real revolution for R/C Aircraft occured in the late 1940's with the invention of the transistor, which then started to become common in electrical equipment from the mid 1950's onwards. The transistor miniaturised electronic circuits from the previous "valves" and made a dramatic impact for the human race in the use of technology. The equipment was now small enough to be transported in a model aircraft.
Early equipment was very basic and often home built. Many transmitters were just single channel which only allowed the manipulation of the rudder. The engine was started, the model launched, and it flew until the engine ran out of "gas" allowing the model to then glide to the ground. At this time the transmitters only allowed simple on/off control i.e. the rudder could only be controlled to right, left, and neutral.
As the electronics revolution took off, these single channel designs became redundant, and by the 1970's proportional coded signal stream could be transmitted. This allowed the operator to "proportionally" move a control surface such as a rudder i.e. instead just selecting full left or full right, the operator could now select a small amount of left, or a small amount of right. The control surface moved proportionally in accordance with the operators input.
The issue of today is the allocation of frequencies to connect the transmitter and receiver. With the growth in wireless technologies worldwide, the radio "space" is getting ever more crowded. In the last ten years 2.4 gigahertz systems have become increasingly utilised in radio control. Initially expensive, these radio systems range from a couple of thousand dollars all the way down to under $30 for simple models made in China.
